The present disclosure relates to a chip resistor.
In accordance with the trend for the multi-functionalization of mobile devices and improvements in the performance thereof, the use of batteries has increased. Therefore, demand for a chip resistor (CSR) has increased for efficiently managing batteries and detecting charging and discharging currents in a pulse code modulation (PCM) circuit.
In recent times within the electric and electronic products market, as the portability of electronic products has been emphasized, the miniaturization of chip resistors used in electronic products has been demanded.
Currently, 1.0 mm×0.5 mm and 0.6 mm×0.3 mm chip resistors have been released onto the market, while 0.4 mm×0.2 mm chip resistors are scheduled for development and release onto the market.
A chip resistor according to the related art may include a substrate, first and second electrodes formed on both ends of the substrate, respectively, resistors connected to the first and second electrodes, an internal protecting layer and an external protecting layer protecting the resistors, and a plating layer enclosing an outer portion of the substrate.
The external protecting layer may be formed of glass or a polymer and may later be covered by a plating layer.
In this case, since adhesion between the external protecting layer and the plating layer is weak, a small interval between a coating part and the plating layer may be formed. Therefore, the first and second electrodes may be partially exposed, such that electrodes containing silver may be oxidized.
Particularly, in the case in which ambient air contains a sulfur compound such as H2S, electrodes containing silver may be destroyed by the sulfur compound, such that the chip resistor may be damaged.
According to the related art, as one method for preventing the above-mentioned sulfuration phenomenon, the first and second electrodes have been formed of a metal having sulfur resistance.
That is, Au, Ag, and Pd, noble metals, and alloys thereof, have been used as a material for the first and second electrodes.
In addition, as another method for preventing the above-mentioned sulfuration phenomenon, terminals have been sealed so that the electrodes are not in contact with ambient air.
However, according to the related art, noble metals have been used, leading to an increase in manufacturing costs.
Further, in the case in which the terminals are sealed, securing sufficient contact force between the plating layer and the protecting layer has been problematic, and a thick resistor has been formed. Therefore, a thickness of the resistor has been excessively increased, such that there have been many difficulties in designing resistor chips.